Merge branch 'maint'

* maint:
  remote: create fetch config lines with '+'
  push: allow unqualified dest refspecs to DWIM
  doc/git-gc: add a note about what is collected
  t5516: remove ambiguity test (1)
  Linked glossary from cvs-migration page
  write-tree: properly detect failure to write tree objects

Documentation/cvs-migration.txt

@@ -8,7 +8,8 @@ designating a single shared repository which people can synchronize with;
 this document explains how to do that.
 
 Some basic familiarity with git is required.  This
-link:tutorial.html[tutorial introduction to git] should be sufficient.
+link:tutorial.html[tutorial introduction to git] and the
+link:glossary.html[git glossary] should be sufficient.
 
 Developing against a shared repository
 --------------------------------------

Documentation/git-gc.txt

@@ -104,6 +104,21 @@ The optional configuration variable 'gc.pruneExpire' controls how old
 the unreferenced loose objects have to be before they are pruned.  The
 default is "2 weeks ago".
 
+
+Notes
+-----
+
+git-gc tries very hard to be safe about the garbage it collects. In
+particular, it will keep not only objects referenced by your current set
+of branches and tags, but also objects referenced by the index, remote
+tracking branches, refs saved by linkgit:git-filter-branch[1] in
+refs/original/, or reflogs (which may references commits in branches
+that were later amended or rewound).
+
+If you are expecting some objects to be collected and they aren't, check
+all of those locations and decide whether it makes sense in your case to
+remove those references.
+
 See Also
 --------
 linkgit:git-prune[1]

builtin-remote.c

@@ -107,6 +107,7 @@ static int add(int argc, const char **argv)
 		struct path_list_item *item = track.items + i;
 
 		strbuf_reset(&buf2);
+		strbuf_addch(&buf2, '+');
 		if (mirror)
 			strbuf_addf(&buf2, "refs/%s:refs/%s",
 					item->path, item->path);

cache-tree.c

@@ -341,8 +341,11 @@ static int update_one(struct cache_tree *it,
 
 	if (dryrun)
 		hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
-	else
+	else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {
-		write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);
+		strbuf_release(&buffer);
+		return -1;
+	}
+
 	strbuf_release(&buffer);
 	it->entry_count = i;
 #if DEBUG

remote.c

@@ -812,6 +812,26 @@ static struct ref *make_linked_ref(const char *name, struct ref ***tail)
 	return ret;
 }
 
+static char *guess_ref(const char *name, struct ref *peer)
+{
+	struct strbuf buf = STRBUF_INIT;
+	unsigned char sha1[20];
+
+	const char *r = resolve_ref(peer->name, sha1, 1, NULL);
+	if (!r)
+		return NULL;
+
+	if (!prefixcmp(r, "refs/heads/"))
+		strbuf_addstr(&buf, "refs/heads/");
+	else if (!prefixcmp(r, "refs/tags/"))
+		strbuf_addstr(&buf, "refs/tags/");
+	else
+		return NULL;
+
+	strbuf_addstr(&buf, name);
+	return strbuf_detach(&buf, NULL);
+}
+
 static int match_explicit(struct ref *src, struct ref *dst,
 			  struct ref ***dst_tail,
 			  struct refspec *rs,
@@ -820,6 +840,7 @@ static int match_explicit(struct ref *src, struct ref *dst,
 	struct ref *matched_src, *matched_dst;
 
 	const char *dst_value = rs->dst;
+	char *dst_guess;
 
 	if (rs->pattern)
 		return errs;
@@ -866,10 +887,15 @@ static int match_explicit(struct ref *src, struct ref *dst,
 	case 0:
 		if (!memcmp(dst_value, "refs/", 5))
 			matched_dst = make_linked_ref(dst_value, dst_tail);
+		else if((dst_guess = guess_ref(dst_value, matched_src)))
+			matched_dst = make_linked_ref(dst_guess, dst_tail);
 		else
-			error("dst refspec %s does not match any "
+			error("unable to push to unqualified destination: %s\n"
-			      "existing ref on the remote and does "
+			      "The destination refspec neither matches an "
-			      "not start with refs/.", dst_value);
+			      "existing ref on the remote nor\n"
+			      "begins with refs/, and we are unable to "
+			      "guess a prefix based on the source ref.",
+			      dst_value);
 		break;
 	default:
 		matched_dst = NULL;

t/t0004-unwritable.sh

@@ -0,0 +1,67 @@
+#!/bin/sh
+
+test_description='detect unwritable repository and fail correctly'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+	>file &&
+	git add file &&
+	git commit -m initial &&
+	echo >file &&
+	git add file
+
+'
+
+test_expect_success 'write-tree should notice unwritable repository' '
+
+	(
+		chmod a-w .git/objects
+		test_must_fail git write-tree
+	)
+	status=$?
+	chmod 775 .git/objects
+	(exit $status)
+
+'
+
+test_expect_success 'commit should notice unwritable repository' '
+
+	(
+		chmod a-w .git/objects
+		test_must_fail git commit -m second
+	)
+	status=$?
+	chmod 775 .git/objects
+	(exit $status)
+
+'
+
+test_expect_success 'update-index should notice unwritable repository' '
+
+	(
+		echo a >file &&
+		chmod a-w .git/objects
+		test_must_fail git update-index file
+	)
+	status=$?
+	chmod 775 .git/objects
+	(exit $status)
+
+'
+
+test_expect_success 'add should notice unwritable repository' '
+
+	(
+		echo b >file &&
+		chmod a-w .git/objects
+		test_must_fail git add file
+	)
+	status=$?
+	chmod 775 .git/objects
+	(exit $status)
+
+'
+
+test_done

t/t5505-remote.sh

@@ -77,6 +77,16 @@ test_expect_success 'add another remote' '
 )
 '
 
+test_expect_success 'remote forces tracking branches' '
+(
+	cd test &&
+	case `git config remote.second.fetch` in
+	+*) true ;;
+	 *) false ;;
+	esac
+)
+'
+
 test_expect_success 'remove remote' '
 (
 	cd test &&

t/t5516-fetch-push.sh

@@ -209,19 +209,7 @@ test_expect_success 'push with weak ambiguity (2)' '
 
 '
 
-test_expect_success 'push with ambiguity (1)' '
+test_expect_success 'push with ambiguity' '
-
-	mk_test remotes/origin/master remotes/frotz/master &&
-	if git push testrepo master:master
-	then
-		echo "Oops, should have failed"
-		false
-	else
-		check_push_result $the_first_commit remotes/origin/master remotes/frotz/master
-	fi
-'
-
-test_expect_success 'push with ambiguity (2)' '
 
 	mk_test heads/frotz tags/frotz &&
 	if git push testrepo master:frotz
@@ -285,6 +273,37 @@ test_expect_success 'push with colon-less refspec (4)' '
 
 '
 
+test_expect_success 'push head with non-existant, incomplete dest' '
+
+	mk_test &&
+	git push testrepo master:branch &&
+	check_push_result $the_commit heads/branch
+
+'
+
+test_expect_success 'push tag with non-existant, incomplete dest' '
+
+	mk_test &&
+	git tag -f v1.0 &&
+	git push testrepo v1.0:tag &&
+	check_push_result $the_commit tags/tag
+
+'
+
+test_expect_success 'push sha1 with non-existant, incomplete dest' '
+
+	mk_test &&
+	test_must_fail git push testrepo `git rev-parse master`:foo
+
+'
+
+test_expect_success 'push ref expression with non-existant, incomplete dest' '
+
+	mk_test &&
+	test_must_fail git push testrepo master^:branch
+
+'
+
 test_expect_success 'push with HEAD' '
 
 	mk_test heads/master &&
@@ -323,6 +342,15 @@ test_expect_success 'push with +HEAD' '
 
 '
 
+test_expect_success 'push HEAD with non-existant, incomplete dest' '
+
+	mk_test &&
+	git checkout master &&
+	git push testrepo HEAD:branch &&
+	check_push_result $the_commit heads/branch
+
+'
+
 test_expect_success 'push with config remote.*.push = HEAD' '
 
 	mk_test heads/local &&